Conventions Used

Conventions Used
Vishay Semiconductors
Conventions Used in Presenting Technical Data
SYMBOLS AND TERMINOLOGY (ALPHABETICALLY)
A
Radiant sensitive area
sr
Steradian
C
Capacitance
T
Period (duration)
°C
Celsius
T
Temperature
Cj
Junction capacitance
t
Time
Ck
Coupling capacitance
Tamb
Ambient temperature (range)
d
Distance
Tcase
Case temperature
EA
Illumination at standard illuminant A
td
Delay time
Ee
Irradiance (at a point of a surface)
tf
Fall time
Ev
Illuminance (at a point of a surface)
Tj
Junction temperature
f
Frequency
toff
Turn-off time
Ie
Radiant intensity (of a source in a given direction)
ton
Turn-on time
IF
Forward current continuous
tp
Pulse duration
IFM
Peak forward current
tpi
Input pulse duration
IOH
High level output current
tpo
Output pulse duration
Iph
Photocurrent (photoelectric current)
tr
Rise time
Ira
Reverse light current
ts
Storage time
Iro
Reverse dark current
Tsd
Soldering temperature
ISD
Supply current in dark ambient
Tstg
Storage temperature range
ISH
Supply current in bright ambient
VCEsat
Collector emitter saturation voltage
Iv
Luminous intensity (of a source, in a given direction)
VEBO
Emitter base voltage, open collector
K
Kelvin
VECO
Emitter collector voltage, open base
lm
Lumen
VF
Forward voltage
lx
Lux
VO
Output voltage
NEP
Noise equivalent power
VOH
Output voltage high
Pdiss
Power dissipation, general
VOL
Output voltage low
Ptot
Total power dissipation
VR
Reverse voltage
RIO
Input/output isolation resistor
VS, VCC Supply voltage
Ris
Isolation resistance
ϕ = α/2
Angle of half sensitivity, Angle of half intensity
RL
Load resistance
ϕ1/2
Angle of half transmission distance
RthJA
Thermal resistance, junction to ambient
λ
Wavelength, general
RthJC
Thermal resistance, junction to case
λ0.5
Range of spectral bandwidth (50 %)
S
Sensitivity, absolute
λp
Wavelength of peak sensitivity or peak emission
s(λ)
Absolute spectral sensitivity at a wavelength λ
Δλ
Spectral half bandwidth
s(λ)rel
Spectral sensitivity, relative
Φe
Radiant flux, radiant power
s(λ0)
Spectral sensitivity at a reference wavelength λ0
Ω
Solid angle
s(λp)
Spectral sensitivity at a reference wavelength λp
Document Number: 84697
Rev. 1.5, 21-Aug-08
www.vishay.com
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